/* * Copyright (C) 2012 - Virtual Open Systems and Columbia University * Author: Christoffer Dall * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License, version 2, as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "trace.h" static pgd_t *boot_hyp_pgd; static pgd_t *hyp_pgd; static pgd_t *merged_hyp_pgd; static DEFINE_MUTEX(kvm_hyp_pgd_mutex); static unsigned long hyp_idmap_start; static unsigned long hyp_idmap_end; static phys_addr_t hyp_idmap_vector; #define S2_PGD_SIZE (PTRS_PER_S2_PGD * sizeof(pgd_t)) #define hyp_pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t)) #define KVM_S2PTE_FLAG_IS_IOMAP (1UL << 0) #define KVM_S2_FLAG_LOGGING_ACTIVE (1UL << 1) static bool memslot_is_logging(struct kvm_memory_slot *memslot) { return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY); } /** * kvm_flush_remote_tlbs() - flush all VM TLB entries for v7/8 * @kvm: pointer to kvm structure. * * Interface to HYP function to flush all VM TLB entries */ void kvm_flush_remote_tlbs(struct kvm *kvm) { kvm_call_hyp(__kvm_tlb_flush_vmid, kvm); } static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa) { kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa); } /* * D-Cache management functions. They take the page table entries by * value, as they are flushing the cache using the kernel mapping (or * kmap on 32bit). */ static void kvm_flush_dcache_pte(pte_t pte) { __kvm_flush_dcache_pte(pte); } static void kvm_flush_dcache_pmd(pmd_t pmd) { __kvm_flush_dcache_pmd(pmd); } static void kvm_flush_dcache_pud(pud_t pud) { __kvm_flush_dcache_pud(pud); } static bool kvm_is_device_pfn(unsigned long pfn) { return !pfn_valid(pfn); } /** * stage2_dissolve_pmd() - clear and flush huge PMD entry * @kvm: pointer to kvm structure. * @addr: IPA * @pmd: pmd pointer for IPA * * Function clears a PMD entry, flushes addr 1st and 2nd stage TLBs. Marks all * pages in the range dirty. */ static void stage2_dissolve_pmd(struct kvm *kvm, phys_addr_t addr, pmd_t *pmd) { if (!pmd_thp_or_huge(*pmd)) return; pmd_clear(pmd); kvm_tlb_flush_vmid_ipa(kvm, addr); put_page(virt_to_page(pmd)); } static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache, int min, int max) { void *page; BUG_ON(max > KVM_NR_MEM_OBJS); if (cache->nobjs >= min) return 0; while (cache->nobjs < max) { page = (void *)__get_free_page(PGALLOC_GFP); if (!page) return -ENOMEM; cache->objects[cache->nobjs++] = page; } return 0; } static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc) { while (mc->nobjs) free_page((unsigned long)mc->objects[--mc->nobjs]); } static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc) { void *p; BUG_ON(!mc || !mc->nobjs); p = mc->objects[--mc->nobjs]; return p; } static void clear_stage2_pgd_entry(struct kvm *kvm, pgd_t *pgd, phys_addr_t addr) { pud_t *pud_table __maybe_unused = stage2_pud_offset(pgd, 0UL); stage2_pgd_clear(pgd); kvm_tlb_flush_vmid_ipa(kvm, addr); stage2_pud_free(pud_table); put_page(virt_to_page(pgd)); } static void clear_stage2_pud_entry(struct kvm *kvm, pud_t *pud, phys_addr_t addr) { pmd_t *pmd_table __maybe_unused = stage2_pmd_offset(pud, 0); VM_BUG_ON(stage2_pud_huge(*pud)); stage2_pud_clear(pud); kvm_tlb_flush_vmid_ipa(kvm, addr); stage2_pmd_free(pmd_table); put_page(virt_to_page(pud)); } static void clear_stage2_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr) { pte_t *pte_table = pte_offset_kernel(pmd, 0); VM_BUG_ON(pmd_thp_or_huge(*pmd)); pmd_clear(pmd); kvm_tlb_flush_vmid_ipa(kvm, addr); pte_free_kernel(NULL, pte_table); put_page(virt_to_page(pmd)); } /* * Unmapping vs dcache management: * * If a guest maps certain memory pages as uncached, all writes will * bypass the data cache and go directly to RAM. However, the CPUs * can still speculate reads (not writes) and fill cache lines with * data. * * Those cache lines will be *clean* cache lines though, so a * clean+invalidate operation is equivalent to an invalidate * operation, because no cache lines are marked dirty. * * Those clean cache lines could be filled prior to an uncached write * by the guest, and the cache coherent IO subsystem would therefore * end up writing old data to disk. * * This is why right after unmapping a page/section and invalidating * the corresponding TLBs, we call kvm_flush_dcache_p*() to make sure * the IO subsystem will never hit in the cache. */ static void unmap_stage2_ptes(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr, phys_addr_t end) { phys_addr_t start_addr = addr; pte_t *pte, *start_pte; start_pte = pte = pte_offset_kernel(pmd, addr); do { if (!pte_none(*pte)) { pte_t old_pte = *pte; kvm_set_pte(pte, __pte(0)); kvm_tlb_flush_vmid_ipa(kvm, addr); /* No need to invalidate the cache for device mappings */ if (!kvm_is_device_pfn(pte_pfn(old_pte))) kvm_flush_dcache_pte(old_pte); put_page(virt_to_page(pte)); } } while (pte++, addr += PAGE_SIZE, addr != end); if (stage2_pte_table_empty(start_pte)) clear_stage2_pmd_entry(kvm, pmd, start_addr); } static void unmap_stage2_pmds(struct kvm *kvm, pud_t *pud, phys_addr_t addr, phys_addr_t end) { phys_addr_t next, start_addr = addr; pmd_t *pmd, *start_pmd; start_pmd = pmd = stage2_pmd_offset(pud, addr); do { next = stage2_pmd_addr_end(addr, end); if (!pmd_none(*pmd)) { if (pmd_thp_or_huge(*pmd)) { pmd_t old_pmd = *pmd; pmd_clear(pmd); kvm_tlb_flush_vmid_ipa(kvm, addr); kvm_flush_dcache_pmd(old_pmd); put_page(virt_to_page(pmd)); } else { unmap_stage2_ptes(kvm, pmd, addr, next); } } } while (pmd++, addr = next, addr != end); if (stage2_pmd_table_empty(start_pmd)) clear_stage2_pud_entry(kvm, pud, start_addr); } static void unmap_stage2_puds(struct kvm *kvm, pgd_t *pgd, phys_addr_t addr, phys_addr_t end) { phys_addr_t next, start_addr = addr; pud_t *pud, *start_pud; start_pud = pud = stage2_pud_offset(pgd, addr); do { next = stage2_pud_addr_end(addr, end); if (!stage2_pud_none(*pud)) { if (stage2_pud_huge(*pud)) { pud_t old_pud = *pud; stage2_pud_clear(pud); kvm_tlb_flush_vmid_ipa(kvm, addr); kvm_flush_dcache_pud(old_pud); put_page(virt_to_page(pud)); } else { unmap_stage2_pmds(kvm, pud, addr, next); } } } while (pud++, addr = next, addr != end); if (stage2_pud_table_empty(start_pud)) clear_stage2_pgd_entry(kvm, pgd, start_addr); } /** * unmap_stage2_range -- Clear stage2 page table entries to unmap a range * @kvm: The VM pointer * @start: The intermediate physical base address of the range to unmap * @size: The size of the area to unmap * * Clear a range of stage-2 mappings, lowering the various ref-counts. Must * be called while holding mmu_lock (unless for freeing the stage2 pgd before * destroying the VM), otherwise another faulting VCPU may come in and mess * with things behind our backs. */ static void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size) { pgd_t *pgd; phys_addr_t addr = start, end = start + size; phys_addr_t next; assert_spin_locked(&kvm->mmu_lock); pgd = kvm->arch.pgd + stage2_pgd_index(addr); do { /* * Make sure the page table is still active, as another thread * could have possibly freed the page table, while we released * the lock. */ if (!READ_ONCE(kvm->arch.pgd)) break; next = stage2_pgd_addr_end(addr, end); if (!stage2_pgd_none(*pgd)) unmap_stage2_puds(kvm, pgd, addr, next); /* * If the range is too large, release the kvm->mmu_lock * to prevent starvation and lockup detector warnings. */ if (next != end) cond_resched_lock(&kvm->mmu_lock); } while (pgd++, addr = next, addr != end); } static void stage2_flush_ptes(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr, phys_addr_t end) { pte_t *pte; pte = pte_offset_kernel(pmd, addr); do { if (!pte_none(*pte) && !kvm_is_device_pfn(pte_pfn(*pte))) kvm_flush_dcache_pte(*pte); } while (pte++, addr += PAGE_SIZE, addr != end); } static void stage2_flush_pmds(struct kvm *kvm, pud_t *pud, phys_addr_t addr, phys_addr_t end) { pmd_t *pmd; phys_addr_t next; pmd = stage2_pmd_offset(pud, addr); do { next = stage2_pmd_addr_end(addr, end); if (!pmd_none(*pmd)) { if (pmd_thp_or_huge(*pmd)) kvm_flush_dcache_pmd(*pmd); else stage2_flush_ptes(kvm, pmd, addr, next); } } while (pmd++, addr = next, addr != end); } static void stage2_flush_puds(struct kvm *kvm, pgd_t *pgd, phys_addr_t addr, phys_addr_t end) { pud_t *pud; phys_addr_t next; pud = stage2_pud_offset(pgd, addr); do { next = stage2_pud_addr_end(addr, end); if (!stage2_pud_none(*pud)) { if (stage2_pud_huge(*pud)) kvm_flush_dcache_pud(*pud); else stage2_flush_pmds(kvm, pud, addr, next); } } while (pud++, addr = next, addr != end); } static void stage2_flush_memslot(struct kvm *kvm, struct kvm_memory_slot *memslot) { phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT; phys_addr_t end = addr + PAGE_SIZE * memslot->npages; phys_addr_t next; pgd_t *pgd; pgd = kvm->arch.pgd + stage2_pgd_index(addr); do { next = stage2_pgd_addr_end(addr, end); stage2_flush_puds(kvm, pgd, addr, next); } while (pgd++, addr = next, addr != end); } /** * stage2_flush_vm - Invalidate cache for pages mapped in stage 2 * @kvm: The struct kvm pointer * * Go through the stage 2 page tables and invalidate any cache lines * backing memory already mapped to the VM. */ static void stage2_flush_vm(struct kvm *kvm) { struct kvm_memslots *slots; struct kvm_memory_slot *memslot; int idx; idx = srcu_read_lock(&kvm->srcu); spin_lock(&kvm->mmu_lock); slots = kvm_memslots(kvm); kvm_for_each_memslot(memslot, slots) stage2_flush_memslot(kvm, memslot); spin_unlock(&kvm->mmu_lock); srcu_read_unlock(&kvm->srcu, idx); } static void clear_hyp_pgd_entry(pgd_t *pgd) { pud_t *pud_table __maybe_unused = pud_offset(pgd, 0UL); pgd_clear(pgd); pud_free(NULL, pud_table); put_page(virt_to_page(pgd)); } static void clear_hyp_pud_entry(pud_t *pud) { pmd_t *pmd_table __maybe_unused = pmd_offset(pud, 0); VM_BUG_ON(pud_huge(*pud)); pud_clear(pud); pmd_free(NULL, pmd_table); put_page(virt_to_page(pud)); } static void clear_hyp_pmd_entry(pmd_t *pmd) { pte_t *pte_table = pte_offset_kernel(pmd, 0); VM_BUG_ON(pmd_thp_or_huge(*pmd)); pmd_clear(pmd); pte_free_kernel(NULL, pte_table); put_page(virt_to_page(pmd)); } static void unmap_hyp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end) { pte_t *pte, *start_pte; start_pte = pte = pte_offset_kernel(pmd, addr); do { if (!pte_none(*pte)) { kvm_set_pte(pte, __pte(0)); put_page(virt_to_page(pte)); } } while (pte++, addr += PAGE_SIZE, addr != end); if (hyp_pte_table_empty(start_pte)) clear_hyp_pmd_entry(pmd); } static void unmap_hyp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end) { phys_addr_t next; pmd_t *pmd, *start_pmd; start_pmd = pmd = pmd_offset(pud, addr); do { next = pmd_addr_end(addr, end); /* Hyp doesn't use huge pmds */ if (!pmd_none(*pmd)) unmap_hyp_ptes(pmd, addr, next); } while (pmd++, addr = next, addr != end); if (hyp_pmd_table_empty(start_pmd)) clear_hyp_pud_entry(pud); } static void unmap_hyp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end) { phys_addr_t next; pud_t *pud, *start_pud; start_pud = pud = pud_offset(pgd, addr); do { next = pud_addr_end(addr, end); /* Hyp doesn't use huge puds */ if (!pud_none(*pud)) unmap_hyp_pmds(pud, addr, next); } while (pud++, addr = next, addr != end); if (hyp_pud_table_empty(start_pud)) clear_hyp_pgd_entry(pgd); } static void unmap_hyp_range(pgd_t *pgdp, phys_addr_t start, u64 size) { pgd_t *pgd; phys_addr_t addr = start, end = start + size; phys_addr_t next; /* * We don't unmap anything from HYP, except at the hyp tear down. * Hence, we don't have to invalidate the TLBs here. */ pgd = pgdp + pgd_index(addr); do { next = pgd_addr_end(addr, end); if (!pgd_none(*pgd)) unmap_hyp_puds(pgd, addr, next); } while (pgd++, addr = next, addr != end); } /** * free_hyp_pgds - free Hyp-mode page tables * * Assumes hyp_pgd is a page table used strictly in Hyp-mode and * therefore contains either mappings in the kernel memory area (above * PAGE_OFFSET), or device mappings in the vmalloc range (from * VMALLOC_START to VMALLOC_END). * * boot_hyp_pgd should only map two pages for the init code. */ void free_hyp_pgds(void) { mutex_lock(&kvm_hyp_pgd_mutex); if (boot_hyp_pgd) { unmap_hyp_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE); free_pages((unsigned long)boot_hyp_pgd, hyp_pgd_order); boot_hyp_pgd = NULL; } if (hyp_pgd) { unmap_hyp_range(hyp_pgd, hyp_idmap_start, PAGE_SIZE); unmap_hyp_range(hyp_pgd, kern_hyp_va(PAGE_OFFSET), (uintptr_t)high_memory - PAGE_OFFSET); unmap_hyp_range(hyp_pgd, kern_hyp_va(VMALLOC_START), VMALLOC_END - VMALLOC_START); free_pages((unsigned long)hyp_pgd, hyp_pgd_order); hyp_pgd = NULL; } if (merged_hyp_pgd) { clear_page(merged_hyp_pgd); free_page((unsigned long)merged_hyp_pgd); merged_hyp_pgd = NULL; } mutex_unlock(&kvm_hyp_pgd_mutex); } static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start, unsigned long end, unsigned long pfn, pgprot_t prot) { pte_t *pte; unsigned long addr; addr = start; do { pte = pte_offset_kernel(pmd, addr); kvm_set_pte(pte, pfn_pte(pfn, prot)); get_page(virt_to_page(pte)); kvm_flush_dcache_to_poc(pte, sizeof(*pte)); pfn++; } while (addr += PAGE_SIZE, addr != end); } static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start, unsigned long end, unsigned long pfn, pgprot_t prot) { pmd_t *pmd; pte_t *pte; unsigned long addr, next; addr = start; do { pmd = pmd_offset(pud, addr); BUG_ON(pmd_sect(*pmd)); if (pmd_none(*pmd)) { pte = pte_alloc_one_kernel(NULL, addr); if (!pte) { kvm_err("Cannot allocate Hyp pte\n"); return -ENOMEM; } pmd_populate_kernel(NULL, pmd, pte); get_page(virt_to_page(pmd)); kvm_flush_dcache_to_poc(pmd, sizeof(*pmd)); } next = pmd_addr_end(addr, end); create_hyp_pte_mappings(pmd, addr, next, pfn, prot); pfn += (next - addr) >> PAGE_SHIFT; } while (addr = next, addr != end); return 0; } static int create_hyp_pud_mappings(pgd_t *pgd, unsigned long start, unsigned long end, unsigned long pfn, pgprot_t prot) { pud_t *pud; pmd_t *pmd; unsigned long addr, next; int ret; addr = start; do { pud = pud_offset(pgd, addr); if (pud_none_or_clear_bad(pud)) { pmd = pmd_alloc_one(NULL, addr); if (!pmd) { kvm_err("Cannot allocate Hyp pmd\n"); return -ENOMEM; } pud_populate(NULL, pud, pmd); get_page(virt_to_page(pud)); kvm_flush_dcache_to_poc(pud, sizeof(*pud)); } next = pud_addr_end(addr, end); ret = create_hyp_pmd_mappings(pud, addr, next, pfn, prot); if (ret) return ret; pfn += (next - addr) >> PAGE_SHIFT; } while (addr = next, addr != end); return 0; } static int __create_hyp_mappings(pgd_t *pgdp, unsigned long ptrs_per_pgd, unsigned long start, unsigned long end, unsigned long pfn, pgprot_t prot) { pgd_t *pgd; pud_t *pud; unsigned long addr, next; int err = 0; mutex_lock(&kvm_hyp_pgd_mutex); addr = start & PAGE_MASK; end = PAGE_ALIGN(end); do { pgd = pgdp + ((addr >> PGDIR_SHIFT) & (ptrs_per_pgd - 1)); if (pgd_none(*pgd)) { pud = pud_alloc_one(NULL, addr); if (!pud) { kvm_err("Cannot allocate Hyp pud\n"); err = -ENOMEM; goto out; } pgd_populate(NULL, pgd, pud); get_page(virt_to_page(pgd)); kvm_flush_dcache_to_poc(pgd, sizeof(*pgd)); } next = pgd_addr_end(addr, end); err = create_hyp_pud_mappings(pgd, addr, next, pfn, prot); if (err) goto out; pfn += (next - addr) >> PAGE_SHIFT; } while (addr = next, addr != end); out: mutex_unlock(&kvm_hyp_pgd_mutex); return err; } static phys_addr_t kvm_kaddr_to_phys(void *kaddr) { if (!is_vmalloc_addr(kaddr)) { BUG_ON(!virt_addr_valid(kaddr)); return __pa(kaddr); } else { return page_to_phys(vmalloc_to_page(kaddr)) + offset_in_page(kaddr); } } /** * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode * @from: The virtual kernel start address of the range * @to: The virtual kernel end address of the range (exclusive) * @prot: The protection to be applied to this range * * The same virtual address as the kernel virtual address is also used * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying * physical pages. */ int create_hyp_mappings(void *from, void *to, pgprot_t prot) { phys_addr_t phys_addr; unsigned long virt_addr; unsigned long start = kern_hyp_va((unsigned long)from); unsigned long end = kern_hyp_va((unsigned long)to); if (is_kernel_in_hyp_mode()) return 0; start = start & PAGE_MASK; end = PAGE_ALIGN(end); for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) { int err; phys_addr = kvm_kaddr_to_phys(from + virt_addr - start); err = __create_hyp_mappings(hyp_pgd, PTRS_PER_PGD, virt_addr, virt_addr + PAGE_SIZE, __phys_to_pfn(phys_addr), prot); if (err) return err; } return 0; } /** * create_hyp_io_mappings - Map IO into both kernel and HYP * @phys_addr: The physical start address which gets mapped * @size: Size of the region being mapped * @kaddr: Kernel VA for this mapping * * The resulting HYP VA is the same as the kernel VA, modulo * HYP_PAGE_OFFSET. */ int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size, void __iomem **kaddr) { unsigned long start, end; *kaddr = ioremap(phys_addr, size); if (!*kaddr) return -ENOMEM; if (is_kernel_in_hyp_mode()) { return 0; } start = kern_hyp_va((unsigned long)*kaddr); end = kern_hyp_va((unsigned long)*kaddr + size); return __create_hyp_mappings(hyp_pgd, PTRS_PER_PGD, start, end, __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE); } /** * kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation. * @kvm: The KVM struct pointer for the VM. * * Allocates only the stage-2 HW PGD level table(s) (can support either full * 40-bit input addresses or limited to 32-bit input addresses). Clears the * allocated pages. * * Note we don't need locking here as this is only called when the VM is * created, which can only be done once. */ int kvm_alloc_stage2_pgd(struct kvm *kvm) { pgd_t *pgd; if (kvm->arch.pgd != NULL) { kvm_err("kvm_arch already initialized?\n"); return -EINVAL; } /* Allocate the HW PGD, making sure that each page gets its own refcount */ pgd = alloc_pages_exact(S2_PGD_SIZE, GFP_KERNEL | __GFP_ZERO); if (!pgd) return -ENOMEM; kvm->arch.pgd = pgd; return 0; } static void stage2_unmap_memslot(struct kvm *kvm, struct kvm_memory_slot *memslot) { hva_t hva = memslot->userspace_addr; phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT; phys_addr_t size = PAGE_SIZE * memslot->npages; hva_t reg_end = hva + size; /* * A memory region could potentially cover multiple VMAs, and any holes * between them, so iterate over all of them to find out if we should * unmap any of them. * * +--------------------------------------------+ * +---------------+----------------+ +----------------+ * | : VMA 1 | VMA 2 | | VMA 3 : | * +---------------+----------------+ +----------------+ * | memory region | * +--------------------------------------------+ */ do { struct vm_area_struct *vma = find_vma(current->mm, hva); hva_t vm_start, vm_end; if (!vma || vma->vm_start >= reg_end) break; /* * Take the intersection of this VMA with the memory region */ vm_start = max(hva, vma->vm_start); vm_end = min(reg_end, vma->vm_end); if (!(vma->vm_flags & VM_PFNMAP)) { gpa_t gpa = addr + (vm_start - memslot->userspace_addr); unmap_stage2_range(kvm, gpa, vm_end - vm_start); } hva = vm_end; } while (hva < reg_end); } /** * stage2_unmap_vm - Unmap Stage-2 RAM mappings * @kvm: The struct kvm pointer * * Go through the memregions and unmap any reguler RAM * backing memory already mapped to the VM. */ void stage2_unmap_vm(struct kvm *kvm) { struct kvm_memslots *slots; struct kvm_memory_slot *memslot; int idx; idx = srcu_read_lock(&kvm->srcu); down_read(¤t->mm->mmap_sem); spin_lock(&kvm->mmu_lock); slots = kvm_memslots(kvm); kvm_for_each_memslot(memslot, slots) stage2_unmap_memslot(kvm, memslot); spin_unlock(&kvm->mmu_lock); up_read(¤t->mm->mmap_sem); srcu_read_unlock(&kvm->srcu, idx); } /** * kvm_free_stage2_pgd - free all stage-2 tables * @kvm: The KVM struct pointer for the VM. * * Walks the level-1 page table pointed to by kvm->arch.pgd and frees all * underlying level-2 and level-3 tables before freeing the actual level-1 table * and setting the struct pointer to NULL. */ void kvm_free_stage2_pgd(struct kvm *kvm) { void *pgd = NULL; spin_lock(&kvm->mmu_lock); if (kvm->arch.pgd) { unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE); pgd = READ_ONCE(kvm->arch.pgd); kvm->arch.pgd = NULL; } spin_unlock(&kvm->mmu_lock); /* Free the HW pgd, one page at a time */ if (pgd) free_pages_exact(pgd, S2_PGD_SIZE); } static pud_t *stage2_get_pud(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, phys_addr_t addr) { pgd_t *pgd; pud_t *pud; pgd = kvm->arch.pgd + stage2_pgd_index(addr); if (WARN_ON(stage2_pgd_none(*pgd))) { if (!cache) return NULL; pud = mmu_memory_cache_alloc(cache); stage2_pgd_populate(pgd, pud); get_page(virt_to_page(pgd)); } return stage2_pud_offset(pgd, addr); } static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, phys_addr_t addr) { pud_t *pud; pmd_t *pmd; pud = stage2_get_pud(kvm, cache, addr); if (!pud) return NULL; if (stage2_pud_none(*pud)) { if (!cache) return NULL; pmd = mmu_memory_cache_alloc(cache); stage2_pud_populate(pud, pmd); get_page(virt_to_page(pud)); } return stage2_pmd_offset(pud, addr); } static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, phys_addr_t addr, const pmd_t *new_pmd) { pmd_t *pmd, old_pmd; pmd = stage2_get_pmd(kvm, cache, addr); VM_BUG_ON(!pmd); /* * Mapping in huge pages should only happen through a fault. If a * page is merged into a transparent huge page, the individual * subpages of that huge page should be unmapped through MMU * notifiers before we get here. * * Merging of CompoundPages is not supported; they should become * splitting first, unmapped, merged, and mapped back in on-demand. */ VM_BUG_ON(pmd_present(*pmd) && pmd_pfn(*pmd) != pmd_pfn(*new_pmd)); old_pmd = *pmd; if (pmd_present(old_pmd)) { pmd_clear(pmd); kvm_tlb_flush_vmid_ipa(kvm, addr); } else { get_page(virt_to_page(pmd)); } kvm_set_pmd(pmd, *new_pmd); return 0; } static bool stage2_is_exec(struct kvm *kvm, phys_addr_t addr) { pmd_t *pmdp; pte_t *ptep; pmdp = stage2_get_pmd(kvm, NULL, addr); if (!pmdp || pmd_none(*pmdp) || !pmd_present(*pmdp)) return false; if (pmd_thp_or_huge(*pmdp)) return kvm_s2pmd_exec(pmdp); ptep = pte_offset_kernel(pmdp, addr); if (!ptep || pte_none(*ptep) || !pte_present(*ptep)) return false; return kvm_s2pte_exec(ptep); } static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, phys_addr_t addr, const pte_t *new_pte, unsigned long flags) { pmd_t *pmd; pte_t *pte, old_pte; bool iomap = flags & KVM_S2PTE_FLAG_IS_IOMAP; bool logging_active = flags & KVM_S2_FLAG_LOGGING_ACTIVE; VM_BUG_ON(logging_active && !cache); /* Create stage-2 page table mapping - Levels 0 and 1 */ pmd = stage2_get_pmd(kvm, cache, addr); if (!pmd) { /* * Ignore calls from kvm_set_spte_hva for unallocated * address ranges. */ return 0; } /* * While dirty page logging - dissolve huge PMD, then continue on to * allocate page. */ if (logging_active) stage2_dissolve_pmd(kvm, addr, pmd); /* Create stage-2 page mappings - Level 2 */ if (pmd_none(*pmd)) { if (!cache) return 0; /* ignore calls from kvm_set_spte_hva */ pte = mmu_memory_cache_alloc(cache); pmd_populate_kernel(NULL, pmd, pte); get_page(virt_to_page(pmd)); } pte = pte_offset_kernel(pmd, addr); if (iomap && pte_present(*pte)) return -EFAULT; /* Create 2nd stage page table mapping - Level 3 */ old_pte = *pte; if (pte_present(old_pte)) { kvm_set_pte(pte, __pte(0)); kvm_tlb_flush_vmid_ipa(kvm, addr); } else { get_page(virt_to_page(pte)); } kvm_set_pte(pte, *new_pte); return 0; } #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG static int stage2_ptep_test_and_clear_young(pte_t *pte) { if (pte_young(*pte)) { *pte = pte_mkold(*pte); return 1; } return 0; } #else static int stage2_ptep_test_and_clear_young(pte_t *pte) { return __ptep_test_and_clear_young(pte); } #endif static int stage2_pmdp_test_and_clear_young(pmd_t *pmd) { return stage2_ptep_test_and_clear_young((pte_t *)pmd); } /** * kvm_phys_addr_ioremap - map a device range to guest IPA * * @kvm: The KVM pointer * @guest_ipa: The IPA at which to insert the mapping * @pa: The physical address of the device * @size: The size of the mapping */ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, phys_addr_t pa, unsigned long size, bool writable) { phys_addr_t addr, end; int ret = 0; unsigned long pfn; struct kvm_mmu_memory_cache cache = { 0, }; end = (guest_ipa + size + PAGE_SIZE - 1) & PAGE_MASK; pfn = __phys_to_pfn(pa); for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) { pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE); if (writable) pte = kvm_s2pte_mkwrite(pte); ret = mmu_topup_memory_cache(&cache, KVM_MMU_CACHE_MIN_PAGES, KVM_NR_MEM_OBJS); if (ret) goto out; spin_lock(&kvm->mmu_lock); ret = stage2_set_pte(kvm, &cache, addr, &pte, KVM_S2PTE_FLAG_IS_IOMAP); spin_unlock(&kvm->mmu_lock); if (ret) goto out; pfn++; } out: mmu_free_memory_cache(&cache); return ret; } static bool transparent_hugepage_adjust(kvm_pfn_t *pfnp, phys_addr_t *ipap) { kvm_pfn_t pfn = *pfnp; gfn_t gfn = *ipap >> PAGE_SHIFT; if (PageTransCompoundMap(pfn_to_page(pfn))) { unsigned long mask; /* * The address we faulted on is backed by a transparent huge * page. However, because we map the compound huge page and * not the individual tail page, we need to transfer the * refcount to the head page. We have to be careful that the * THP doesn't start to split while we are adjusting the * refcounts. * * We are sure this doesn't happen, because mmu_notifier_retry * was successful and we are holding the mmu_lock, so if this * THP is trying to split, it will be blocked in the mmu * notifier before touching any of the pages, specifically * before being able to call __split_huge_page_refcount(). * * We can therefore safely transfer the refcount from PG_tail * to PG_head and switch the pfn from a tail page to the head * page accordingly. */ mask = PTRS_PER_PMD - 1; VM_BUG_ON((gfn & mask) != (pfn & mask)); if (pfn & mask) { *ipap &= PMD_MASK; kvm_release_pfn_clean(pfn); pfn &= ~mask; kvm_get_pfn(pfn); *pfnp = pfn; } return true; } return false; } static bool kvm_is_write_fault(struct kvm_vcpu *vcpu) { if (kvm_vcpu_trap_is_iabt(vcpu)) return false; return kvm_vcpu_dabt_iswrite(vcpu); } /** * stage2_wp_ptes - write protect PMD range * @pmd: pointer to pmd entry * @addr: range start address * @end: range end address */ static void stage2_wp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end) { pte_t *pte; pte = pte_offset_kernel(pmd, addr); do { if (!pte_none(*pte)) { if (!kvm_s2pte_readonly(pte)) kvm_set_s2pte_readonly(pte); } } while (pte++, addr += PAGE_SIZE, addr != end); } /** * stage2_wp_pmds - write protect PUD range * @pud: pointer to pud entry * @addr: range start address * @end: range end address */ static void stage2_wp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end) { pmd_t *pmd; phys_addr_t next; pmd = stage2_pmd_offset(pud, addr); do { next = stage2_pmd_addr_end(addr, end); if (!pmd_none(*pmd)) { if (pmd_thp_or_huge(*pmd)) { if (!kvm_s2pmd_readonly(pmd)) kvm_set_s2pmd_readonly(pmd); } else { stage2_wp_ptes(pmd, addr, next); } } } while (pmd++, addr = next, addr != end); } /** * stage2_wp_puds - write protect PGD range * @pgd: pointer to pgd entry * @addr: range start address * @end: range end address * * Process PUD entries, for a huge PUD we cause a panic. */ static void stage2_wp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end) { pud_t *pud; phys_addr_t next; pud = stage2_pud_offset(pgd, addr); do { next = stage2_pud_addr_end(addr, end); if (!stage2_pud_none(*pud)) { /* TODO:PUD not supported, revisit later if supported */ BUG_ON(stage2_pud_huge(*pud)); stage2_wp_pmds(pud, addr, next); } } while (pud++, addr = next, addr != end); } /** * stage2_wp_range() - write protect stage2 memory region range * @kvm: The KVM pointer * @addr: Start address of range * @end: End address of range */ static void stage2_wp_range(struct kvm *kvm, phys_addr_t addr, phys_addr_t end) { pgd_t *pgd; phys_addr_t next; pgd = kvm->arch.pgd + stage2_pgd_index(addr); do { /* * Release kvm_mmu_lock periodically if the memory region is * large. Otherwise, we may see kernel panics with * CONFIG_DETECT_HUNG_TASK, CONFIG_LOCKUP_DETECTOR, * CONFIG_LOCKDEP. Additionally, holding the lock too long * will also starve other vCPUs. We have to also make sure * that the page tables are not freed while we released * the lock. */ cond_resched_lock(&kvm->mmu_lock); if (!READ_ONCE(kvm->arch.pgd)) break; next = stage2_pgd_addr_end(addr, end); if (stage2_pgd_present(*pgd)) stage2_wp_puds(pgd, addr, next); } while (pgd++, addr = next, addr != end); } /** * kvm_mmu_wp_memory_region() - write protect stage 2 entries for memory slot * @kvm: The KVM pointer * @slot: The memory slot to write protect * * Called to start logging dirty pages after memory region * KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns * all present PMD and PTEs are write protected in the memory region. * Afterwards read of dirty page log can be called. * * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired, * serializing operations for VM memory regions. */ void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot) { struct kvm_memslots *slots = kvm_memslots(kvm); struct kvm_memory_slot *memslot = id_to_memslot(slots, slot); phys_addr_t start = memslot->base_gfn << PAGE_SHIFT; phys_addr_t end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT; spin_lock(&kvm->mmu_lock); stage2_wp_range(kvm, start, end); spin_unlock(&kvm->mmu_lock); kvm_flush_remote_tlbs(kvm); } /** * kvm_mmu_write_protect_pt_masked() - write protect dirty pages * @kvm: The KVM pointer * @slot: The memory slot associated with mask * @gfn_offset: The gfn offset in memory slot * @mask: The mask of dirty pages at offset 'gfn_offset' in this memory * slot to be write protected * * Walks bits set in mask write protects the associated pte's. Caller must * acquire kvm_mmu_lock. */ static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn_offset, unsigned long mask) { phys_addr_t base_gfn = slot->base_gfn + gfn_offset; phys_addr_t start = (base_gfn + __ffs(mask)) << PAGE_SHIFT; phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT; stage2_wp_range(kvm, start, end); } /* * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected * dirty pages. * * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to * enable dirty logging for them. */ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn_offset, unsigned long mask) { kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); } static void clean_dcache_guest_page(kvm_pfn_t pfn, unsigned long size) { __clean_dcache_guest_page(pfn, size); } static void invalidate_icache_guest_page(kvm_pfn_t pfn, unsigned long size) { __invalidate_icache_guest_page(pfn, size); } static void kvm_send_hwpoison_signal(unsigned long address, struct vm_area_struct *vma) { siginfo_t info; info.si_signo = SIGBUS; info.si_errno = 0; info.si_code = BUS_MCEERR_AR; info.si_addr = (void __user *)address; if (is_vm_hugetlb_page(vma)) info.si_addr_lsb = huge_page_shift(hstate_vma(vma)); else info.si_addr_lsb = PAGE_SHIFT; send_sig_info(SIGBUS, &info, current); } static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, struct kvm_memory_slot *memslot, unsigned long hva, unsigned long fault_status) { int ret; bool write_fault, exec_fault, writable, hugetlb = false, force_pte = false; unsigned long mmu_seq; gfn_t gfn = fault_ipa >> PAGE_SHIFT; struct kvm *kvm = vcpu->kvm; struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache; struct vm_area_struct *vma; kvm_pfn_t pfn; pgprot_t mem_type = PAGE_S2; bool logging_active = memslot_is_logging(memslot); unsigned long flags = 0; write_fault = kvm_is_write_fault(vcpu); exec_fault = kvm_vcpu_trap_is_iabt(vcpu); VM_BUG_ON(write_fault && exec_fault); if (fault_status == FSC_PERM && !write_fault && !exec_fault) { kvm_err("Unexpected L2 read permission error\n"); return -EFAULT; } /* Let's check if we will get back a huge page backed by hugetlbfs */ down_read(¤t->mm->mmap_sem); vma = find_vma_intersection(current->mm, hva, hva + 1); if (unlikely(!vma)) { kvm_err("Failed to find VMA for hva 0x%lx\n", hva); up_read(¤t->mm->mmap_sem); return -EFAULT; } if (vma_kernel_pagesize(vma) == PMD_SIZE && !logging_active) { hugetlb = true; gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT; } else { /* * Pages belonging to memslots that don't have the same * alignment for userspace and IPA cannot be mapped using * block descriptors even if the pages belong to a THP for * the process, because the stage-2 block descriptor will * cover more than a single THP and we loose atomicity for * unmapping, updates, and splits of the THP or other pages * in the stage-2 block range. */ if ((memslot->userspace_addr & ~PMD_MASK) != ((memslot->base_gfn << PAGE_SHIFT) & ~PMD_MASK)) force_pte = true; } up_read(¤t->mm->mmap_sem); /* We need minimum second+third level pages */ ret = mmu_topup_memory_cache(memcache, KVM_MMU_CACHE_MIN_PAGES, KVM_NR_MEM_OBJS); if (ret) return ret; mmu_seq = vcpu->kvm->mmu_notifier_seq; /* * Ensure the read of mmu_notifier_seq happens before we call * gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk * the page we just got a reference to gets unmapped before we have a * chance to grab the mmu_lock, which ensure that if the page gets * unmapped afterwards, the call to kvm_unmap_hva will take it away * from us again properly. This smp_rmb() interacts with the smp_wmb() * in kvm_mmu_notifier_invalidate_. */ smp_rmb(); pfn = gfn_to_pfn_prot(kvm, gfn, write_fault, &writable); if (pfn == KVM_PFN_ERR_HWPOISON) { kvm_send_hwpoison_signal(hva, vma); return 0; } if (is_error_noslot_pfn(pfn)) return -EFAULT; if (kvm_is_device_pfn(pfn)) { mem_type = PAGE_S2_DEVICE; flags |= KVM_S2PTE_FLAG_IS_IOMAP; } else if (logging_active) { /* * Faults on pages in a memslot with logging enabled * should not be mapped with huge pages (it introduces churn * and performance degradation), so force a pte mapping. */ force_pte = true; flags |= KVM_S2_FLAG_LOGGING_ACTIVE; /* * Only actually map the page as writable if this was a write * fault. */ if (!write_fault) writable = false; } spin_lock(&kvm->mmu_lock); if (mmu_notifier_retry(kvm, mmu_seq)) goto out_unlock; if (!hugetlb && !force_pte) hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa); if (hugetlb) { pmd_t new_pmd = pfn_pmd(pfn, mem_type); new_pmd = pmd_mkhuge(new_pmd); if (writable) { new_pmd = kvm_s2pmd_mkwrite(new_pmd); kvm_set_pfn_dirty(pfn); } if (fault_status != FSC_PERM) clean_dcache_guest_page(pfn, PMD_SIZE); if (exec_fault) { new_pmd = kvm_s2pmd_mkexec(new_pmd); invalidate_icache_guest_page(pfn, PMD_SIZE); } else if (fault_status == FSC_PERM) { /* Preserve execute if XN was already cleared */ if (stage2_is_exec(kvm, fault_ipa)) new_pmd = kvm_s2pmd_mkexec(new_pmd); } ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd); } else { pte_t new_pte = pfn_pte(pfn, mem_type); if (writable) { new_pte = kvm_s2pte_mkwrite(new_pte); kvm_set_pfn_dirty(pfn); mark_page_dirty(kvm, gfn); } if (fault_status != FSC_PERM) clean_dcache_guest_page(pfn, PAGE_SIZE); if (exec_fault) { new_pte = kvm_s2pte_mkexec(new_pte); invalidate_icache_guest_page(pfn, PAGE_SIZE); } else if (fault_status == FSC_PERM) { /* Preserve execute if XN was already cleared */ if (stage2_is_exec(kvm, fault_ipa)) new_pte = kvm_s2pte_mkexec(new_pte); } ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags); } out_unlock: spin_unlock(&kvm->mmu_lock); kvm_set_pfn_accessed(pfn); kvm_release_pfn_clean(pfn); return ret; } /* * Resolve the access fault by making the page young again. * Note that because the faulting entry is guaranteed not to be * cached in the TLB, we don't need to invalidate anything. * Only the HW Access Flag updates are supported for Stage 2 (no DBM), * so there is no need for atomic (pte|pmd)_mkyoung operations. */ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) { pmd_t *pmd; pte_t *pte; kvm_pfn_t pfn; bool pfn_valid = false; trace_kvm_access_fault(fault_ipa); spin_lock(&vcpu->kvm->mmu_lock); pmd = stage2_get_pmd(vcpu->kvm, NULL, fault_ipa); if (!pmd || pmd_none(*pmd)) /* Nothing there */ goto out; if (pmd_thp_or_huge(*pmd)) { /* THP, HugeTLB */ *pmd = pmd_mkyoung(*pmd); pfn = pmd_pfn(*pmd); pfn_valid = true; goto out; } pte = pte_offset_kernel(pmd, fault_ipa); if (pte_none(*pte)) /* Nothing there either */ goto out; *pte = pte_mkyoung(*pte); /* Just a page... */ pfn = pte_pfn(*pte); pfn_valid = true; out: spin_unlock(&vcpu->kvm->mmu_lock); if (pfn_valid) kvm_set_pfn_accessed(pfn); } /** * kvm_handle_guest_abort - handles all 2nd stage aborts * @vcpu: the VCPU pointer * @run: the kvm_run structure * * Any abort that gets to the host is almost guaranteed to be caused by a * missing second stage translation table entry, which can mean that either the * guest simply needs more memory and we must allocate an appropriate page or it * can mean that the guest tried to access I/O memory, which is emulated by user * space. The distinction is based on the IPA causing the fault and whether this * memory region has been registered as standard RAM by user space. */ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run) { unsigned long fault_status; phys_addr_t fault_ipa; struct kvm_memory_slot *memslot; unsigned long hva; bool is_iabt, write_fault, writable; gfn_t gfn; int ret, idx; fault_status = kvm_vcpu_trap_get_fault_type(vcpu); fault_ipa = kvm_vcpu_get_fault_ipa(vcpu); is_iabt = kvm_vcpu_trap_is_iabt(vcpu); /* Synchronous External Abort? */ if (kvm_vcpu_dabt_isextabt(vcpu)) { /* * For RAS the host kernel may handle this abort. * There is no need to pass the error into the guest. */ if (!handle_guest_sea(fault_ipa, kvm_vcpu_get_hsr(vcpu))) return 1; if (unlikely(!is_iabt)) { kvm_inject_vabt(vcpu); return 1; } } trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu), kvm_vcpu_get_hfar(vcpu), fault_ipa); /* Check the stage-2 fault is trans. fault or write fault */ if (fault_status != FSC_FAULT && fault_status != FSC_PERM && fault_status != FSC_ACCESS) { kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n", kvm_vcpu_trap_get_class(vcpu), (unsigned long)kvm_vcpu_trap_get_fault(vcpu), (unsigned long)kvm_vcpu_get_hsr(vcpu)); return -EFAULT; } idx = srcu_read_lock(&vcpu->kvm->srcu); gfn = fault_ipa >> PAGE_SHIFT; memslot = gfn_to_memslot(vcpu->kvm, gfn); hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable); write_fault = kvm_is_write_fault(vcpu); if (kvm_is_error_hva(hva) || (write_fault && !writable)) { if (is_iabt) { /* Prefetch Abort on I/O address */ kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu)); ret = 1; goto out_unlock; } /* * Check for a cache maintenance operation. Since we * ended-up here, we know it is outside of any memory * slot. But we can't find out if that is for a device, * or if the guest is just being stupid. The only thing * we know for sure is that this range cannot be cached. * * So let's assume that the guest is just being * cautious, and skip the instruction. */ if (kvm_vcpu_dabt_is_cm(vcpu)) { kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu)); ret = 1; goto out_unlock; } /* * The IPA is reported as [MAX:12], so we need to * complement it with the bottom 12 bits from the * faulting VA. This is always 12 bits, irrespective * of the page size. */ fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1); ret = io_mem_abort(vcpu, run, fault_ipa); goto out_unlock; } /* Userspace should not be able to register out-of-bounds IPAs */ VM_BUG_ON(fault_ipa >= KVM_PHYS_SIZE); if (fault_status == FSC_ACCESS) { handle_access_fault(vcpu, fault_ipa); ret = 1; goto out_unlock; } ret = user_mem_abort(vcpu, fault_ipa, memslot, hva, fault_status); if (ret == 0) ret = 1; out_unlock: srcu_read_unlock(&vcpu->kvm->srcu, idx); return ret; } static int handle_hva_to_gpa(struct kvm *kvm, unsigned long start, unsigned long end, int (*handler)(struct kvm *kvm, gpa_t gpa, u64 size, void *data), void *data) { struct kvm_memslots *slots; struct kvm_memory_slot *memslot; int ret = 0; slots = kvm_memslots(kvm); /* we only care about the pages that the guest sees */ kvm_for_each_memslot(memslot, slots) { unsigned long hva_start, hva_end; gfn_t gpa; hva_start = max(start, memslot->userspace_addr); hva_end = min(end, memslot->userspace_addr + (memslot->npages << PAGE_SHIFT)); if (hva_start >= hva_end) continue; gpa = hva_to_gfn_memslot(hva_start, memslot) << PAGE_SHIFT; ret |= handler(kvm, gpa, (u64)(hva_end - hva_start), data); } return ret; } static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data) { unmap_stage2_range(kvm, gpa, size); return 0; } int kvm_unmap_hva(struct kvm *kvm, unsigned long hva) { unsigned long end = hva + PAGE_SIZE; if (!kvm->arch.pgd) return 0; trace_kvm_unmap_hva(hva); handle_hva_to_gpa(kvm, hva, end, &kvm_unmap_hva_handler, NULL); return 0; } int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end) { if (!kvm->arch.pgd) return 0; trace_kvm_unmap_hva_range(start, end); handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL); return 0; } static int kvm_set_spte_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data) { pte_t *pte = (pte_t *)data; WARN_ON(size != PAGE_SIZE); /* * We can always call stage2_set_pte with KVM_S2PTE_FLAG_LOGGING_ACTIVE * flag clear because MMU notifiers will have unmapped a huge PMD before * calling ->change_pte() (which in turn calls kvm_set_spte_hva()) and * therefore stage2_set_pte() never needs to clear out a huge PMD * through this calling path. */ stage2_set_pte(kvm, NULL, gpa, pte, 0); return 0; } void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte) { unsigned long end = hva + PAGE_SIZE; pte_t stage2_pte; if (!kvm->arch.pgd) return; trace_kvm_set_spte_hva(hva); stage2_pte = pfn_pte(pte_pfn(pte), PAGE_S2); handle_hva_to_gpa(kvm, hva, end, &kvm_set_spte_handler, &stage2_pte); } static int kvm_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data) { pmd_t *pmd; pte_t *pte; WARN_ON(size != PAGE_SIZE && size != PMD_SIZE); pmd = stage2_get_pmd(kvm, NULL, gpa); if (!pmd || pmd_none(*pmd)) /* Nothing there */ return 0; if (pmd_thp_or_huge(*pmd)) /* THP, HugeTLB */ return stage2_pmdp_test_and_clear_young(pmd); pte = pte_offset_kernel(pmd, gpa); if (pte_none(*pte)) return 0; return stage2_ptep_test_and_clear_young(pte); } static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data) { pmd_t *pmd; pte_t *pte; WARN_ON(size != PAGE_SIZE && size != PMD_SIZE); pmd = stage2_get_pmd(kvm, NULL, gpa); if (!pmd || pmd_none(*pmd)) /* Nothing there */ return 0; if (pmd_thp_or_huge(*pmd)) /* THP, HugeTLB */ return pmd_young(*pmd); pte = pte_offset_kernel(pmd, gpa); if (!pte_none(*pte)) /* Just a page... */ return pte_young(*pte); return 0; } int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end) { if (!kvm->arch.pgd) return 0; trace_kvm_age_hva(start, end); return handle_hva_to_gpa(kvm, start, end, kvm_age_hva_handler, NULL); } int kvm_test_age_hva(struct kvm *kvm, unsigned long hva) { if (!kvm->arch.pgd) return 0; trace_kvm_test_age_hva(hva); return handle_hva_to_gpa(kvm, hva, hva, kvm_test_age_hva_handler, NULL); } void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu) { mmu_free_memory_cache(&vcpu->arch.mmu_page_cache); } phys_addr_t kvm_mmu_get_httbr(void) { if (__kvm_cpu_uses_extended_idmap()) return virt_to_phys(merged_hyp_pgd); else return virt_to_phys(hyp_pgd); } phys_addr_t kvm_get_idmap_vector(void) { return hyp_idmap_vector; } static int kvm_map_idmap_text(pgd_t *pgd) { int err; /* Create the idmap in the boot page tables */ err = __create_hyp_mappings(pgd, __kvm_idmap_ptrs_per_pgd(), hyp_idmap_start, hyp_idmap_end, __phys_to_pfn(hyp_idmap_start), PAGE_HYP_EXEC); if (err) kvm_err("Failed to idmap %lx-%lx\n", hyp_idmap_start, hyp_idmap_end); return err; } int kvm_mmu_init(void) { int err; hyp_idmap_start = kvm_virt_to_phys(__hyp_idmap_text_start); hyp_idmap_end = kvm_virt_to_phys(__hyp_idmap_text_end); hyp_idmap_vector = kvm_virt_to_phys(__kvm_hyp_init); /* * We rely on the linker script to ensure at build time that the HYP * init code does not cross a page boundary. */ BUG_ON((hyp_idmap_start ^ (hyp_idmap_end - 1)) & PAGE_MASK); kvm_debug("IDMAP page: %lx\n", hyp_idmap_start); kvm_debug("HYP VA range: %lx:%lx\n", kern_hyp_va(PAGE_OFFSET), kern_hyp_va((unsigned long)high_memory - 1)); if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) && hyp_idmap_start < kern_hyp_va(~0UL) && hyp_idmap_start != (unsigned long)__hyp_idmap_text_start) { /* * The idmap page is intersecting with the VA space, * it is not safe to continue further. */ kvm_err("IDMAP intersecting with HYP VA, unable to continue\n"); err = -EINVAL; goto out; } hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order); if (!hyp_pgd) { kvm_err("Hyp mode PGD not allocated\n"); err = -ENOMEM; goto out; } if (__kvm_cpu_uses_extended_idmap()) { boot_hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order); if (!boot_hyp_pgd) { kvm_err("Hyp boot PGD not allocated\n"); err = -ENOMEM; goto out; } err = kvm_map_idmap_text(boot_hyp_pgd); if (err) goto out; merged_hyp_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO); if (!merged_hyp_pgd) { kvm_err("Failed to allocate extra HYP pgd\n"); goto out; } __kvm_extend_hypmap(boot_hyp_pgd, hyp_pgd, merged_hyp_pgd, hyp_idmap_start); } else { err = kvm_map_idmap_text(hyp_pgd); if (err) goto out; } return 0; out: free_hyp_pgds(); return err; } void kvm_arch_commit_memory_region(struct kvm *kvm, const struct kvm_userspace_memory_region *mem, const struct kvm_memory_slot *old, const struct kvm_memory_slot *new, enum kvm_mr_change change) { /* * At this point memslot has been committed and there is an * allocated dirty_bitmap[], dirty pages will be be tracked while the * memory slot is write protected. */ if (change != KVM_MR_DELETE && mem->flags & KVM_MEM_LOG_DIRTY_PAGES) kvm_mmu_wp_memory_region(kvm, mem->slot); } int kvm_arch_prepare_memory_region(struct kvm *kvm, struct kvm_memory_slot *memslot, const struct kvm_userspace_memory_region *mem, enum kvm_mr_change change) { hva_t hva = mem->userspace_addr; hva_t reg_end = hva + mem->memory_size; bool writable = !(mem->flags & KVM_MEM_READONLY); int ret = 0; if (change != KVM_MR_CREATE && change != KVM_MR_MOVE && change != KVM_MR_FLAGS_ONLY) return 0; /* * Prevent userspace from creating a memory region outside of the IPA * space addressable by the KVM guest IPA space. */ if (memslot->base_gfn + memslot->npages >= (KVM_PHYS_SIZE >> PAGE_SHIFT)) return -EFAULT; down_read(¤t->mm->mmap_sem); /* * A memory region could potentially cover multiple VMAs, and any holes * between them, so iterate over all of them to find out if we can map * any of them right now. * * +--------------------------------------------+ * +---------------+----------------+ +----------------+ * | : VMA 1 | VMA 2 | | VMA 3 : | * +---------------+----------------+ +----------------+ * | memory region | * +--------------------------------------------+ */ do { struct vm_area_struct *vma = find_vma(current->mm, hva); hva_t vm_start, vm_end; if (!vma || vma->vm_start >= reg_end) break; /* * Mapping a read-only VMA is only allowed if the * memory region is configured as read-only. */ if (writable && !(vma->vm_flags & VM_WRITE)) { ret = -EPERM; break; } /* * Take the intersection of this VMA with the memory region */ vm_start = max(hva, vma->vm_start); vm_end = min(reg_end, vma->vm_end); if (vma->vm_flags & VM_PFNMAP) { gpa_t gpa = mem->guest_phys_addr + (vm_start - mem->userspace_addr); phys_addr_t pa; pa = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT; pa += vm_start - vma->vm_start; /* IO region dirty page logging not allowed */ if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES) { ret = -EINVAL; goto out; } ret = kvm_phys_addr_ioremap(kvm, gpa, pa, vm_end - vm_start, writable); if (ret) break; } hva = vm_end; } while (hva < reg_end); if (change == KVM_MR_FLAGS_ONLY) goto out; spin_lock(&kvm->mmu_lock); if (ret) unmap_stage2_range(kvm, mem->guest_phys_addr, mem->memory_size); else stage2_flush_memslot(kvm, memslot); spin_unlock(&kvm->mmu_lock); out: up_read(¤t->mm->mmap_sem); return ret; } void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free, struct kvm_memory_slot *dont) { } int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot, unsigned long npages) { return 0; } void kvm_arch_memslots_updated(struct kvm *kvm, struct kvm_memslots *slots) { } void kvm_arch_flush_shadow_all(struct kvm *kvm) { kvm_free_stage2_pgd(kvm); } void kvm_arch_flush_shadow_memslot(struct kvm *kvm, struct kvm_memory_slot *slot) { gpa_t gpa = slot->base_gfn << PAGE_SHIFT; phys_addr_t size = slot->npages << PAGE_SHIFT; spin_lock(&kvm->mmu_lock); unmap_stage2_range(kvm, gpa, size); spin_unlock(&kvm->mmu_lock); } /* * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized). * * Main problems: * - S/W ops are local to a CPU (not broadcast) * - We have line migration behind our back (speculation) * - System caches don't support S/W at all (damn!) * * In the face of the above, the best we can do is to try and convert * S/W ops to VA ops. Because the guest is not allowed to infer the * S/W to PA mapping, it can only use S/W to nuke the whole cache, * which is a rather good thing for us. * * Also, it is only used when turning caches on/off ("The expected * usage of the cache maintenance instructions that operate by set/way * is associated with the cache maintenance instructions associated * with the powerdown and powerup of caches, if this is required by * the implementation."). * * We use the following policy: * * - If we trap a S/W operation, we enable VM trapping to detect * caches being turned on/off, and do a full clean. * * - We flush the caches on both caches being turned on and off. * * - Once the caches are enabled, we stop trapping VM ops. */ void kvm_set_way_flush(struct kvm_vcpu *vcpu) { unsigned long hcr = *vcpu_hcr(vcpu); /* * If this is the first time we do a S/W operation * (i.e. HCR_TVM not set) flush the whole memory, and set the * VM trapping. * * Otherwise, rely on the VM trapping to wait for the MMU + * Caches to be turned off. At that point, we'll be able to * clean the caches again. */ if (!(hcr & HCR_TVM)) { trace_kvm_set_way_flush(*vcpu_pc(vcpu), vcpu_has_cache_enabled(vcpu)); stage2_flush_vm(vcpu->kvm); *vcpu_hcr(vcpu) = hcr | HCR_TVM; } } void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled) { bool now_enabled = vcpu_has_cache_enabled(vcpu); /* * If switching the MMU+caches on, need to invalidate the caches. * If switching it off, need to clean the caches. * Clean + invalidate does the trick always. */ if (now_enabled != was_enabled) stage2_flush_vm(vcpu->kvm); /* Caches are now on, stop trapping VM ops (until a S/W op) */ if (now_enabled) *vcpu_hcr(vcpu) &= ~HCR_TVM; trace_kvm_toggle_cache(*vcpu_pc(vcpu), was_enabled, now_enabled); }